Photos would help us a lot but mint and grey usually goes well with charred oak.

Well you posted this several months ago, but I thought I would make suggestions anyway. Hope you don't mind. In order to stay with or keep in mind the style of the shelves I would first change out the towel rack and TP holder to a chrome, or brushed nickel finish. Or get something that goes with the water faucet on the sink. If you are going to paint the wood around the shower base, paint the window trim and pieces of baseboard that are wood as well. I agree with using a gray color that adalisa, above mentioned. Maybe paint your vanity a darker gray, or even a shade of black, like your shelves to tie it in. That's it for me.

Reconsider not having a bathtub in your large master bath space, which currently has a good bit of wasted space, for your convenience as well as for future buyers. You also don't appear to have any counterspace or storage by the sinks, the shower is big enough that you don't need a door on it, and a small freestanding soaker tub could fit under the window in the wet area of the space if the door to the bathroom was moved a couple of feet up the wall opposite the sinks. You can't put furniture on that wall, anyway, due to the traffic pattern.

Lindsey, I see you have a couple inspiration boards, use ideas for colors, styles, finishes, faucets, counter tops, etc for your new home, just on a smaller scale. Maybe find your dream bath and copy those finishes into your small space. Vanities ideas could include an antique piece repurposed. Tile can be cold, yet, carpet and wood do not do well in wet areas. With that said, there are heating systems available now that are installed beneath the tile to take the chill off. My other trick is using one large rug runner to almost fill the size of the area instead of tiny bath mats.